Connecter plug



Patented Apr. 7, 1936 UNITED STATES PATENT OFFICE CONNECTER PLUG William J. Shore, New York, N. Y.

Application February 9, 1935, Serial No. 5,733

9 Claims. (Cl. 173-332) My invention relates to contact elements or sockets for receiving and engaging contact pins to form an effective electric connection for such appliances as heating elements, at irons, etc.

Heretofore, in devices of this type, the contact elements for receiving and engaging contact pins have been formed of substantially rigid metal strips or elem-ents, spaced to receive the contact pin and pressed by springs to a resilient contact with the surface of the pin inserted between them. The strips were normally pressed inwardly beyond gripping position, so that they would be displaced by the insertion of the pins placing the springs under tension, which would react on the inserted pin. Instead of moving to parallel positions, however, the strips or plates of these prior contact elements were tilted under certain conditions so that instead of contacting with the pin throughout their lengths, the strips formed only a4 point contact therewith and thereby formed a very narrow and ineffective connection. Moreover, as the pin is drawn out from contact elements of the prior type', the current is concentrated at a point or a pair of points, thus increasing the tendency to draw an arc.

These disadvantages are avoided by my present invention, which provides a pin receiving contact of simple inexpensive construction, in which a line or extensive contact is made with the pin under all conditions.

The various features of my invention are illustrated in the accompanying drawing; in which l Fig. 1 is a half section of a connecting plug element of usual construction embodying contact elements of my invention; Fig. 2 is a vertical section of the plug and contact element taken on line 2 2 of Fig. 1; Fig. 3 is a horizontal cross section of the plug and contact elements taken on line 3-3 of Fig. 1; Fig. 4 is a perspective view of a contact element embodying my invention; Fig. 5 is a cross section of the contact element of Fig. l and Fig. 6 is a longitudinal section on line 6 6 of Fig. 5; Figs. 'l and 8 are respectively plan and side views of a piece of metal cut to form a blank from which a contact element embodying my invention may be formed; and Fig. 9 is a blank of different form from which the contact element embodying my invention may be formed.

In the accompanying drawing, the contact elements of my invention are shown as applied to an appliance plug III, such as is commonly employed for fiat irons and which may be formed of a pair of complementary parts II and I2 secured together by bolts I3 and I4 and having recesses I5 arranged symmetrically on opposite sides of the bolts to receive the contact element i6 of my invention and communicating with a groove Il, in which the feed wires I3 may be received. It will be understood that the specific form of plug is illustrated merely by way of eX- 5 ample and that my contact elements may be used in a wide variety of plugs or connecting apparatus.

1n the form of embodiment of the invention shown in Figs. 1 to 6 inclusive, each contact elel0 ment I6 comprises a pair of spaced parallel strips I9 and 2li, connected at their upper ends by a connecting plate 2i, from which extends a mounting plate 22 by means of which the contact elements may be mounted in the plugs by a binding post or screw 23 or by other suitable means. From the side edges of each of the strips IQ, there extend a series of separated wings 2li, 25, Z6 and 2l, which are doubled to a position flat against or almost iiat against the inner faces of the strips i9 and 2li and thence outwardly at an angle, as for example an angle of about 45 degrees to form contact surfaces 23, 29, 3l) and 3l, respectively.

In the embodiment oi the invention illustrated 25 in the drawing, each side edge of each strip is provided, by way of example, with three separate Wings. It will be understood, however, that this is merely by way of example and that any number of wings may be provided to suit the requirements of any particular case. It will also be noted that each of the wings is separated from the adjacent wing until they join the strip` I9 and that the reverse bending of the wing element gives it resiliency. The wings are normally so positioned that when a pin or contact post 32 is inserted between the strips I9 and 2li, the wings will be slightly displaced against the spring action and will thus grip the post 32. To minimize any scraping action of the wings on the post 32 40 and to aid in breaking an arc, as the post is withdrawn, the side edges of the wings are bent outwardly as at 33.

With the above construction, it will be apparent that each of the wing elements 28-3I of 45 each contact element will grip-` the post 32 throughout the entire width of the wing because if the post be inserted only partially it will merely press the wing element with which it contacts against its respective spring individually and will not tilt it longitudinally, as will be the case with longitudinally positioned pivoted or spring pressed contact elements.

Accordingly, applicants invention provides under all circumstances a substantially continuous 56 Cil line contact throughout the length of pin inserted into the elements. Moreover, four such line contacts are formed with each pin, whereas previously it was diiiicult, if not impossible, to insure more than two line contacts for each pin.

The Contact elements may readily be formed integrally from a single piece of sheet metal. For this purpose, the sheet metal may be cut to the form shown in Figs. 7 and 8, providing the strip portions i9 and 2o from which the wings are formed by slitting the metal longitudinally upward on the line 36 and then cutting transverse slits S from each side edge and 36 from the central slit 3G. Upon bending the wings in reverse curves on the lines 3l and 38, respectively, the wing elements are formed on the strips I9 and Ztl. The metal is then bent at right angles on the lines 3S and bringing the strips on their proper spaced relation relative to the central connecting plate '.fi. Notches are formed in the plate at anc to form a neck portion 43, which is bent downwardly on the line le and thence upwardly on the line 55 to position the mounting plate or surface Z2 centrally, as indicated in Fig. 4.

In the modified stamping blank shown in Fig. 9, the two strips i@ and 25.1* are shown end to end and the wings E8 to 3i are formed merely by slitting inwardly from opposite sides. The wings o may then be shaped by bending on lines 38 and 3l, as in Fig. '7. rThe elements are then completed by bending on the lines indicated at 4t, which corresponds to the line im of Fig. 7, then on the lines il which correspond to the lines i5 of Fig. 7 and then on the central line 8 to bring the strips into their proper spaced relation.

It will thus be apparent that the contacts may be easily made from a single blank of sheet metal by suitably slitting and bending or stamping operations.

It will be noted that each of the contact wings 8-3i acts independently of the other. This insures a multiplicity of contacts even though the pin 32 may be broken or worn or bent or partly destroyed. Moreover, the injury by pitting or otherwise or the breakage or destruction of one or more wings does not destroy the efficiency ci contact of the others.

What I claim is:

1. An electric Contact element comprising a pair of parallel spaced strips and wings extending from each of the longitudinal edges of said strips at longituddnally spaced ters/'als into the space between said strips tow longitudinal axes of said strips, and r bent within said space outwardly i n the central part thereof to bring the inner faces of said wir. s tangent to the :riracey of a contactpin when inserted between said strips.

2. An electric contact element comprising a pair of spaced strips and flat wings extending at longitudinally spaced intervals from each of the longitudinal edges of said strips into the space between said strips and toward the center line of said strips, and thence bent reversely outwardly from the center line of said strips to bring the inner faces of said wings tangent to the surface of a contact pin when inserted between said strips.

3. An electric contact element comprising a pair of parallel spaced strips and spaced at wings extending from the edges of said strips to the space between said strips and reversely bent to bring the inner faces of said wings tangent to the surface of a contact pin when inserted between said strips, the said wings having their side edges turned outwardly.

4. An electric contact element comprising a pair of parallel spaced strips joined by a` connecting plate at the top and having wings extending from the edges of said strips to the space between said strips and reversely bent to bring the inner faces of said wings tangent to the surface of a contact pin when inserted between said strips.

5. An electric contact element comprising a pair of parallel spaced strips joined by a connecting plate at the top and having wings extending from the edges of said strips to the space between said strips and reversely bent to bring the inner faces of said wings tangent to the surface of a contact pin when inserted between said strips, said contact element being formed integrally of a single strip of metal.

6. An electric contact element formed of a sheet or" metal cut and bent to form spaced strips and a connecting plate at the top edges of said strips to hold them in spaced parallel position, the side edges of said strips being slit to form separate wings and said wings being bent inwardly toward said plate and then reversely outwardly to outline a recess of polygonal cross section.

7. An electric contact element comprising a pair of parallel spaced strips, a series of longitudinally spaced contact wings extending from each of the longitudinal edges of said strips and bent at the edges of said strips inwardly into the space between said strips to present a contact face to a plug inserted between said strips, each of said wings being displaceable individually against the spring action of said bent part.

8. An electric contact element comprising a pair of parallel spaced strips, a series of longitudinally spaced Contact wings extending from each of the longitudinal edges of said strips and bent inwardly into the space between said strips to present a contact face to a plug inserted between said strips, each of said wings being displaceable individually against the spring action of said bent part, the edges of said wings transverse to the direction of insertion of the plug being bent away from contact with the plug.

9. An electric contact element comprising a pair of parallel spaced strips, a series of longitudinaily spaced contact wings extending from each of the longitudinal edge-s of said strips and bent inwardly into the space between said strips to present a contact face to a plug inserted between said strips, each of said wings being displaceable individually against the spring action of said bent part, said pair of strips and said wings being formed of a single sheet of metal out and stamped to shape.

WILLIAM J. SHORE. 

